Power semiconductor devices, for examples IGFETs (insulated gate field effect transistors) are typically vertical devices with a load current flow between a first surface at a front side of a semiconductor die and a second surface on the back. In a blocking mode field electrode structures extending from a front side into the semiconductor die deplete a depletable portion of the semiconductor die. The field electrode structures allow high dopant concentrations in the depletable portion without adverse impact on the blocking capability. Higher dopant concentrations in the depletable portion reduce the on-state resistance of the device.
It is desirable to provide semiconductor devices with high avalanche ruggedness.